Rollers of drafting mechanism for textile fibers



J. NOGUERA 2,387,937

ROLLERS OF DRAFTING MECHANISM FOR TEXTILE FIBERS Oct. 30, 1945.

Filed March 5, 1943 Attorneys Patented Oct. 30,1945.

ROLLERS OF DRAFTING MECHANISM FOR TEXTILEFIBERS Joseph Noguera, Prestwich, Manchester, England, assignor to Casablancas High Draft Company Limited, Manchester, England, a British com- ApplicationMarch 3,1943, Serial No. 477,875 In Great. Britain. April 27,1942

7. Claims.

This invention relates to improvements in the rollers of drafting mechanisms for textile fibers.

In: drafting mechanisms used on ma'chines'for drafting. or: spinning. textile fibers, the, drafting rollers. are usually arranged. in consecutive pairs, one roller'offeach pair being. positively drivenand the. other roller. of the. pair, which is frequently covered with cloth and-leather or other soft material', usually driven by frictional contact with the positively-driven roller. Thev strand of fiber being drawn passes in between the rollers, of. each pair so; that in fact the positively-driven, rollers impart their motion to the corresponding friction-driven. rollers through the intermediary of the fibers which are being gripped in between the two; rollers. In the usual arrangement of this kind, the frictionedriven roller is the top roller anld. the positively-driven. roller is the bottom r ler..

Consequently, to ensure that the fibers are effectively gripped and made to. travel. at a speed as nearly correct as possible, the top, frictiondriven rollers are heavily'weighted, but even so,

in actual. practice, a certain. amount of slippage always occurs. Many attempts have been made to overcomethis defect;

One of the. most successful means so far adopted for driving the top, friction-driven rollers at the correct speed. consists in having the top and: bottom rollers of each pair geared together. This has, however, two important disadvantages. In the. first. place, the. gearing driwes thetop roller at a, fixednumber of revolutions in relation to the bottom. roller, whereas the diameter of they said top. rollers is a variable factor when the surface of the toprollers is covered with. cloth and leather or-the like, as-such rollers are never exactly alike intheir, outside diameter andthey also. wear out at: different rates. In addition to this defect, there is also'the, fact that the driving of the top: roller through gears on the bottom roller tends all the time to push the top roller upwards, that is, away from the bottom, roller, thus weakening the contact between the two rollersiandi thereby reducing the efficiency of the grlp-onthefibers.

It is among the objects of the present invention to. provide a drafting arrangement" in which the;friction-driven drafting roller will be kept we'll-againstthe fibers all the time and will revolve at the: same; peripheral. speed irrespectiveof its outside diameter.

According; to the: present invention, ina drafting, mechanism. of. the kind comprising-pairs of drafting rollers each. consisting of. a positively- 1 driven roller and a roller to which motion is imparted by frictional contact with the positivelydriven' roller, said friction-driven roller receives motion by frictional contact of its working surface with an additional positively-driven roller which is not itself a drafting. roller.

The invention will now be described with reference to the accompanying drawing which shows various embodiments of the invention by way of example and in which:

Figure 1 is a view showing a friction-driven soft-covered roller mounted in known manner.

Figures 2 and 3 are end and side elevations showing the friction-driven soft-covered roller mounted in accordance with the present invention.

Figure 4 is a side elevation showing the friction-driven soft-covered rollers mounted according to the present invention and incorporated in a drafting mechanism according to my co-pending application Ser. No. 466,314, filed November 20, 1942.

Figure 5 is a side elevation showing the friction-driven soft-covered rollers mounted according to the present invention and incorporated in v a drafting mechanism according to my co-pending application Ser. No. 469,101, filed December 15, 1942.

Referring to Figure l, which shows the friction-driven soft-covered roller mounted in known manner, the friction-driven soft-covered roller l is mounted with its central pivot 2 held within a slotted support 3 andis driven by frictional contact with a positively driven' roller 4. If the softcovered roller I is eccentrically mounted with respect to the pivot 2, the outer boss 5 must deploy its eccentricity and consequently the nip between the two rollers, i. e. the point at which the fibers are held, moves to and from between positions A and B.

Referring now to Figures 2 and 3, the softcovered roller I is driven by frictional contact with two positively-driven rollers 4 and 6, the roller 6 being disposed on the upper side of the pair of drafting rollers. In the example illustrated, two soft-covered rollers l are connected by a shaft 1 provided with a neck 8 for receiving the usual weighting hook (not shown), which is arranged to exercise a pull in the direction of the arrow 9. As illustrated, the bosses on the soft-covered rollers l are just wide enough to cover the maximum width of the strand which has the effect of. increasing the proportion of the pressure exerted by the top rollers which is applied to the strand.

The rotation of the soft-covered roller is thus not only assisted by two positively-driven rollers instead of one, but the action of the additional roller 6 is especially effective because it contacts with the soft-covered roller direct instead of through the intermediary 'of the strand. Very little pressure from the soft-covered roller is sufficient to secure a firm grip on the fibers and consequently the soft covering of the roller bosses lasts much longer. Furthermore, as'the softcovered roller is not mounted in supports, the friction which usually occurs between the roller and such supports is avoided. The frictiondriven soft-covered roller is always held in a steady and definite position so that the nip which it forms with its coacting drafting roller is always in the same place and the drawback of varying nip position illustrated in Figure 1 is avoided Figure 4 shows the principle of the present invention applied to a drafting mechanism according to my co-pending application Ser. No. 466,314, filed November 11, 1942, in which the endless belts ID for engaging and guiding the fibers are so arranged with respect to the drafting rollers that the strand of fibers is delivered edgewise to said drafting rollers, while the surfaces of said belts which are gripped between the beltdriving rollers II are in a plane at right angles to the plane in which the strand is delivered to the drafting rollers. As before,- reference numeral I denotes the friction-driven soft-covered rollers, 4 the positively-driven rollers normally provided and 6 the additional positively-driven rollers provided according to the present invention.

Figure 5 shows the principle of the present invention applied to a drafting mechanism according to my co-pending application Ser; No. 469,101, filed December 15, 1942, in which pairs of rollers, each consisting of a positively-driven roller 4 and a soft-covered roller I, are so arranged that the strand on leaving each of two consecutive pairs of rollers is pulled round above about a quarter of the surface of one of the rollers of each pair, after which it passes straight into the nip of the succeeding pair. The additional positively-driven rollers provided in accordance with the present invention are denoted by 6.

It will be noted from Figures 4 and 5 that the invention is applicable not only to the usual arrangement in which the friction-driven softcovered roller is mounted on top of the positivelydriven roller, in which case the soft-covered roller is referred to as the top roller and the positively-driven roller asthe bottom roller, but to any other arrangement of the. friction-driven 'soft-covered roller and the positively-driven roller. Thus, it is not necessary for the additional positively-driven rollers 6 to be mounted on the upper side of the drafting mechanism since they may be mounted in any position which allows the soft-covered rollers to rest in between the coacting positively-driven rollers. The softcovered rollers are kept in position by means of the weighting hooks usually employed irrespective of whether the soft-covered rollers are positioned above, below or at the side of their coacting drafting rollers. The direction of the pull exerted by the weighting hooks is indicated by the arrow 9 in Figures 4 and 5.

What I claim and desire to secure by Letters Patent of the United States is:

- 1. For use in a spinning frame with a spinning couple composed of two rolls adapted to receive the roving therebetween, one of the rolls being driven and in turn driving through the roving the other roll, a driven third roll positioned out of the path and out of contact with the roving and in direct driving contact with said other roll. 2. For use with driven and follower spinning rolls having a nip through which the roving passes, a driven third roll having with the follower roll a direct friction driving nip free of the roving.

3. In a spinning frame, an association of three rolls comprising two drawing rolls one of which is a driver and the other an idler and having a nip therebetween through which the driver drives the idler through the roving passing through such nip, and a third non-drawing driver roll frictionally directly engaging the idler at a point removed from said nip .free from the intervention of the roving.

4. In a spinning frame, the combination of claim 3 characterized by the fact that the idler is unsupported save by said driver rolls and is driven only by frictional action of said driver rolls.

5. A spinning frame as claimed in claim 3 in which the idler is a soft-covered roller.

6. A spinning frame as claimed in claim 3, in

whichthe working surface of the idler is just wide enough to cover the maximum width of the roving.

7. A drafting mechanism for textile fibers comprising a series of pairs of upper and lower drafting rolls spaced apart substantially horizontally and having the textile fibers passing substantially horizontally from the nip of one pair of rolls to the nips of the other pairs of rolls in sequence, one roll of each pair being a positively-driven roller, the other roller of the pair being a frictiondriven roller, and positively-driven non-drafting rolls engaging directly and frictionally with the friction-driven rolls at points removed from said nips and free from the intervention of the fibers whereby a direct friction drive is-had.

JOSEPH NOGUERA. 

